|   | 
Details
   web
Records
Author Witte, S.; Villanueva-Domingo, P.; Gariazzo, S.; Mena, O.; Palomares-Ruiz, S.
Title EDGES result versus CMB and low-redshift constraints on ionization histories Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 97 Issue 10 Pages 103533 - 8pp
Keywords
Abstract We examine the results from the Experiment to Detect the Global Epoch of Reionization Signature (EDGES), which has recently claimed the detection of a strong absorption in the 21 cm hyperfine transition line of neutral hydrogen, at redshifts demarcating the early stages of star formation. More concretely, we study the compatibility of the shape of the EDGES absorption profile, centered at a redshift of z similar to 17.2, with measurements of the reionization optical depth, the Gunn-Peterson optical depth, and Lyman-alpha emission from star-forming galaxies, for a variety of possible reionization models within the standard ACDM framework (that is, a Universe with a cosmological constant. and cold dark matter CDM). When, conservatively, we only try to accommodate the location of the absorption dip, we identify a region in the parameter space of the astrophysical parameters that successfully explains all of the aforementioned observations. However, one of the most abnormal features of the EDGES measurement is the absorption amplitude, which is roughly a factor of 2 larger than the maximum allowed value in the ACDM framework. We point out that the simple considered astrophysical models that produce the largest absorption amplitudes are unable to explain the depth of the dip and of reproducing the observed shape of the absorption profile.
Address [Witte, Samuel; Villanueva-Domingo, Pablo; Gariazzo, Stefano; Mena, Olga; Palomares-Ruiz, Sergio] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000433291600010 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 3606
Permanent link to this record
 

 
Author Barenboim, G.; Ternes, C.A.; Tortola, M.
Title Neutrinos, DUNE and the world best bound on CPT invariance Type Journal Article
Year 2018 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 780 Issue Pages 631-637
Keywords Neutrino mass and mixing; Neutrino oscillation; CPT
Abstract CPT symmetry, the combination of Charge Conjugation, Parity and Time reversal, is a cornerstone of our model building strategy and therefore the repercussions of its potential violation will severely threaten the most extended tool we currently use to describe physics, i.e. local relativistic quantum fields. However, limits on its conservation from the Kaon system look indeed imposing. In this work we will show that neutrino oscillation experiments can improve this limit by several orders of magnitude and therefore are an ideal tool to explore the foundations of our approach to Nature. Strictly speaking testing CPT violation would require an explicit model for how CPT is broken and its effects on physics. Instead, what is presented in this paper is a test of one of the predictions of CPT conservation, i.e., the same mass and mixing parameters in neutrinos and antineutrinos. In order to do that we calculate the current CPT bound on all the neutrino mixing parameters and study the sensitivity of the DUNE experiment to such an observable. After deriving the most updated bound on CPT from neutrino oscillation data, we show that, if the recent T2K results turn out to be the true values of neutrino and antineutrino oscillations, DUNE would measure the fallout of CPT conservation at more than 3 sigma. Then, we study the sensitivity of the experiment to measure CPT invariance in general, finding that DUNE will be able to improve the current bounds on Delta(Delta m(31)(2)) by at least one order of magnitude. We also study the sensitivity to the other oscillation parameters. Finally we show that, if CPT is violated in nature, combining neutrino with antineutrino data in oscillation analysis will produce imposter solutions.
Address [Barenboim, G.] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: Gabriela.Barenboim@uv.es;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000432187800085 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 3620
Permanent link to this record
 

 
Author Ferreiro, A.; Navarro-Salas, J.
Title Pair creation in electric fields, anomalies, and renormalization of the electric current Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 97 Issue 12 Pages 125012 - 13pp
Keywords
Abstract We investigate the Schwinger pair production phenomena in spatially homogeneous strong electric fields. We first consider scalar QED in four-dimensions and discuss the potential ambiguity in the adiabatic order assignment for the electromagnetic potential required to fix the renormalization subtractions. We argue that this ambiguity can be solved by invoking the conformal anomaly when both electric and gravitational backgrounds are present. We also extend the adiabatic regularization method for spinor QED in two-dimensions and find consistency with the chiral anomaly. We focus on the issue of the renormalization of the electric current < j(mu)> generated by the created pairs. We illustrate how to implement the renormalization of the electric current for the Sauter pulse.
Address [Ferreiro, Antonio; Navarro-Salas, Jose] Univ Valencia, Dept Fis Teor, Ctr Mixto, CSIC,Fac Fis, E-46100 Valencia, Spain, Email: antonio.ferreiro@ific.uv.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000435335000014 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 3623
Permanent link to this record
 

 
Author Centelles Chulia, S.; Srivastava, R.; Valle, J.W.F.
Title Seesaw roadmap to neutrino mass and dark matter Type Journal Article
Year 2018 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 781 Issue Pages 122-128
Keywords
Abstract We describe the many pathways to generate Majorana and Dirac neutrino mass through generalized dimension-5 operators a la Weinberg. The presence of new scalars beyond the Standard Model Higgs doublet implies new possible field contractions, which are required in the case of Dirac neutrinos. We also notice that, in the Dirac neutrino case, the extra symmetries needed to ensure the Dirac nature of neutrinos can also be made responsible for stability of dark matter.
Address [Chulia, Salvador Centelles; Srivastava, Rahul; Valle, Jose W. F.] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Parc Cientif Paterna,C Catedrat Jose Beltra 2, E-46980 Valencia, Spain, Email: salcen@ific.uv.es;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000435653100016 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 3631
Permanent link to this record
 

 
Author Hirsch, M.; Srivastava, R.; Valle, J.W.F.
Title Can one ever prove that neutrinos are Dirac particles? Type Journal Article
Year 2018 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 781 Issue Pages 302-305
Keywords
Abstract According to the “Black Box” theorem the experimental confirmation of neutrinoless double beta decay (0 nu 2 beta) would imply that at least one of the neutrinos is a Majorana particle. However, a null 0 nu 2 beta signal cannot decide the nature of neutrinos, as it can be suppressed even for Majorana neutrinos. In this letter we argue that if the null 0 nu 2 beta decay signal is accompanied by a 0 nu 2 beta quadruple beta decay signal, then at least one neutrino should be a Dirac particle. This argument holds irrespective of the underlying processes leading to such decays.
Address [Hirsch, Martin; Srivastava, Rahul; Valle, Jose W. F.] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, C Catedrat Jose Beltran 2, E-46980 Valencia, Spain, Email: mahirsch@ific.uv.es;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000435653100039 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 3632
Permanent link to this record
 

 
Author Muñoz, E.; Barrio, J.; Bernabeu, J.; Etxebeste, A.; Lacasta, C.; Llosa, G.; Ros, A.; Roser, J.; Oliver, J.F.
Title Study and comparison of different sensitivity models for a two-plane Compton camera Type Journal Article
Year 2018 Publication Physics in Medicine and Biology Abbreviated Journal Phys. Med. Biol.
Volume 63 Issue 13 Pages 135004 - 19pp
Keywords Compton camera imaging; MLEM; Monte Carlo simulations; image quality
Abstract Given the strong variations in the sensitivity of Compton cameras for the detection of events originating from different points in the field of view (FoV), sensitivity correction is often necessary in Compton image reconstruction. Several approaches for the calculation of the sensitivity matrix have been proposed in the literature. While most of these models are easily implemented and can be useful in many cases, they usually assume high angular coverage over the scattered photon, which is not the case for our prototype. In this work, we have derived an analytical model that allows us to calculate a detailed sensitivity matrix, which has been compared to other sensitivity models in the literature. Specifically, the proposed model describes the probability of measuring a useful event in a two-plane Compton camera, including the most relevant physical processes involved. The model has been used to obtain an expression for the system and sensitivity matrices for iterative image reconstruction. These matrices have been validated taking Monte Carlo simulations as a reference. In order to study the impact of the sensitivity, images reconstructed with our sensitivity model and with other models have been compared. Images have been reconstructed from several simulated sources, including point-like sources and extended distributions of activity, and also from experimental data measured with Na-22 sources. Results show that our sensitivity model is the best suited for our prototype. Although other models in the literature perform successfully in many scenarios, they are not applicable in all the geometrical configurations of interest for our system. In general, our model allows to effectively recover the intensity of point-like sources at different positions in the FoV and to reconstruct regions of homogeneous activity with minimal variance. Moreover, it can be employed for all Compton camera configurations, including those with low angular coverage over the scatterer.
Address [Munoz, Enrique; Barrio, John; Bernabeu, Jose; Etxebeste, Ane; Lacasta, Carlos; Llosa, Gabriela; Ros, Ana; Roser, Jorge; Oliver, Josep F.] Univ Valencia, CSIC, Inst Fis Corpuscular, IFIC, Valencia, Spain, Email: Enrique.Munoz@ific.uv.es
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9155 ISBN Medium
Area Expedition Conference
Notes WOS:000436390800004 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 3639
Permanent link to this record
 

 
Author Gisbert, H.; Pich, A.
Title Direct CP violation in K-0 -> pi pi : Standard Model Status Type Journal Article
Year 2018 Publication Reports on Progress in Physics Abbreviated Journal Rep. Prog. Phys.
Volume 81 Issue 7 Pages 076201 - 22pp
Keywords Kaon decays; CP violation; Standard Model
Abstract In 1988 the NA31 experiment presented the first evidence of direct CP violation in the K-0 -> pi pi decay amplitudes. A clear signal with a 7.2 sigma statistical significance was later established with the full data samples from the NA31, E731, NA48 and KTeV experiments, confirming that CP violation is associated with a Delta S = 1 quark transition, as predicted by the Standard Model. However, the theoretical prediction for the measured ratio epsilon'/epsilon has been a subject of strong controversy along the years. Although the underlying physics was already clarified in 2001, the recent release of improved lattice data has revived again the theoretical debate. We review the current status, discussing in detail the different ingredients that enter into the calculation of this observable and the reasons why seemingly contradictory predictions were obtained in the past by several groups. An update of the Standard Model prediction is presented and the prospects for future improvements are analysed. Taking into account all known short-distance and long-distance contributions, one obtains Re (epsilon' / epsilon) = (15 +/- 7) . 10(-4), in good agreement with the experimental measurement.
Address [Gisbert, Hector; Pich, Antonio] Univ Valencia, CSIC, IFIC, Dept Fis Teor, Apt Correus 22085, E-46071 Valencia, Spain, Email: Antonio.Pich@ific.uv.es
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0034-4885 ISBN Medium
Area Expedition Conference
Notes WOS:000436545600001 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 3641
Permanent link to this record
 

 
Author Pavao, R.; Sakai, S.; Oset, E.
Title Production of N*(1535) and N*(1650) in Lambda(c)-> (K)over-bar(0)eta p (pi N) decay Type Journal Article
Year 2018 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 98 Issue 1 Pages 015201 - 8pp
Keywords
Abstract To study the properties of the N*(1535) and N*(1650), we calculate the mass distributions of MB in the Lambda(c) -> (K) over bar (MB)-M-0 decay, with MB = pi N(I = 1/2), eta p, and K Sigma(I = 1/2). We do this by calculating the tree-level and loop contributions, mixing pseudoscalar-baryon and vector-baryon channels using the local hidden gauge formalism. The loop contributions for each channel are calculated using the chiral unitary approach. We observe that for the eta N mass distribution only the N* (1535) is seen, with the N* (1650) contributing to the width of the curve, but for the pi N mass distribution both resonances are clearly visible. In the case of MB = K Sigma, we found that the strength of the K E mass distribution is smaller than that of the mass distributions of the pi N and eta p in the Lambda(+)(c)-> (K) over bar (0)pi N and Lambda(+)(c) -> (K) over bar (0)eta p processes, in spite of this channel having a large coupling to the N* (1650). This is because the K Sigma pair production is suppressed in the primary production from the Lambda(c) decay.
Address [Pavao, R.] Ctr Mixto Univ Valencia, CSIC Inst Invest Paterna, Dept Fis Teor, Valencia 46071, Spain, Email: rpavao@ific.uv.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000436940200003 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 3643
Permanent link to this record
 

 
Author Vento, V.
Title Skyrmions at high density Type Journal Article
Year 2018 Publication Physics of Particles and Nuclei Letters Abbreviated Journal Phys. Part. Nuclei Lett.
Volume 15 Issue 4 Pages 367-370
Keywords quark; pion; skyrmion; dilation
Abstract The phase diagram of quantum chromodynamics is conjectured to have a rich structure containing at least three forms of matter: hadronic nuclear matter, quarkyonic matter and quark gluon plasma. We describe its formulation in terms of Skyrme crystals and justify the origin of the quarkyonic phase transition in a chiral-quark model.
Address [Vento, V.] Univ Valencia, CSIC, Dept Fis Teor IFIC, E-46100 Burjassot, Valencia, Spain, Email: vicente.vento@uv.es
Corporate Author Thesis
Publisher Pleiades Publishing Inc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1547-4771 ISBN Medium
Area Expedition Conference
Notes WOS:000437770100006 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 3651
Permanent link to this record
 

 
Author Vicente, A.
Title Anomalies in b -> s transitions and dark matter Type Journal Article
Year 2018 Publication Advances in High Energy Physics Abbreviated Journal Adv. High. Energy Phys.
Volume 2018 Issue Pages 3905848 - 11pp
Keywords
Abstract Since 2013, the LHCb collaboration has reported on the measurement of several observables associated with b -> s transitions, finding various deviations from their predicted values in the Standard Model. These include a set of deviations in branching ratios and angular observables, as well as in the observables R-k and R-k*, specially built to test the possible violation of Lepton Flavor Universality. Even though these tantalizing hints are not conclusive yet, the b -> s* anomalies have gained considerable attention in the flavor community. Here we review new physics models that address these anomalies and explore their possible connection to the dark matter of the Universe. After discussing some of the ideas introduced in these works and classifying the proposed models, two selected examples are presented in detail in order to illustrate the potential interplay between these two areas of current particle physics.
Address [Vicente, Avelino] Univ Valencia, CSIC, Inst Fis Corpuscular, Apdo 22085, E-46071 Valencia, Spain, Email: avelino.vicente@ific.uv.es
Corporate Author Thesis
Publisher Hindawi Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1687-7357 ISBN Medium
Area Expedition Conference
Notes WOS:000437956000001 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 3652
Permanent link to this record